Conserving our sawfish – genetic research bridges knowledge gap

Dr Jack Ingelbrecht and team with a green sawfish. Image credit: Dr David Morgan and Dr Jack Ingelbrecht/ Murdoch University.

Researchers from Murdoch University’s Harry Butler Institute have employed the latest genetic techniques to uncover critical breeding and reproductive knowledge about one of the world’s most threatened marine animals – the sawfish. 

Research fellows Dr Jack Ingelbrecht and Associate Professor David Morgan led a team from the Centre for Sustainable Aquatic Ecosystems as they reconstructed a series of family trees for green sawfish in WA’s Ashburton River.   

The green sawfish, known to grow longer than six metres, is critically endangered.   

Classified as critically endangered, the green sawfish is related to the ray family with a shark-like body and an elongated snout containing up to 34 pairs of saw teeth. These “teeth” are modified scales that are used to locate, stun, and kill prey. Image credit: Chevron Australia.

Dr Ingelbrecht said one of the biggest barriers in sawfish conservation was how little is known about breeding populations – with this research bridging a critical gap.  

Using DNA collected over 10 years, researchers discovered that more than 50 female green sawfish had given birth in the Ashburton River estuary in the Pilbara region or nearby tidal creeks between 2011 and 2022.  They further identified that nine of these female sawfish used the area as a birth site on multiple occasions.   

With sawfish believed to be extinct in nearly two dozen countries, and populations continuing to decline, Dr Ingelbrecht said these research findings would aid conservation work.   

“The findings are really important for informing conservation efforts, as they demonstrate that some female green sawfish are actually returning to, and reusing, the same site for pupping,” Dr Ingelbrecht said.  

 “This suggests that conservation efforts for green sawfish could be more effective if targeted towards protecting key waterways like the Ashburton River.”   

Chevron Australia provided funding support for the project and the Chevron Australia Sea Rangers assisted with the monitoring program, bringing valuable Indigenous Knowledge regarding best practices for monitoring waterways on Country. 
 
For more information, read the study here.